• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
Sign in to follow this  
Followers 0
lipsryme

Deferred renderer + shadow mapping

7 posts in this topic

A quick question.

Do I understand it correct, that I have to render my entire geometry twice for directional light shadows ?

 

1. Shadow map pass

2. Render geometry again for the projection ?

 

That sounds horrible :/

 

0

Share this post


Link to post
Share on other sites
No, the advantage of deferred rendering is, that you don't need to render the whole geometry again for the projection part, a fullscreen quad or some bounding volume is enough. In this case you reconstruct the world position from the g-buffer and use it to project it into light space to access the shadow map. Edited by Ashaman73
0

Share this post


Link to post
Share on other sites
Well, he still needs to render geometry for shadow map with different projection matrix. I think thats what he asked? But thats not really connected to deferred rendering. (according to his 2 bullets at least, maybe he meant what you answered actually) Edited by noizex
0

Share this post


Link to post
Share on other sites
@noizex no I know that a geometry pass is needed for the light's depth (shadow map), but what I don't know is how to project this using a Fullscreen-quad pass (?)

@Ashaman73 Can you tell me how this works or do you have some sample code, because I've been trying to implement this for quite some time without any luck this far...
How do I project this onto the quad texture instead of geometry ?
I'm talking about a directional light which is implemented as a FSQ post effect and using orthographic projection for the shadow map. Edited by lipsryme
0

Share this post


Link to post
Share on other sites
When applying the directional light as a FSQ you will reconstruct the world space position for the pixel being shaded. This world space position can then be transformed into light space and the shadow map and comparison done. Is it this transform from world space to light space that you are having trouble with?
0

Share this post


Link to post
Share on other sites

I am using function for projection and depth comparison:

//Position - world position of objects from G-buffer
float shadowCast(float3 Position)
{
	float4 texcoord = mul(float4(Position, 1.0), LightInvertViewProjection);
	texcoord.x = ((texcoord.x / texcoord.w) * 0.5 ) + 0.5;
	texcoord.y = ((texcoord.y / texcoord.w) * -0.5 ) + 0.5;
	depth = tex2D(shadows, texcoord.xy);
	return (texcoord.z < length(depth)*bias+offset);
}

It works well for me, don't forget to tweak bias and offset to reduce acne and peter paning smile.png

.

0

Share this post


Link to post
Share on other sites

For your original question, yes, you do need to render your geometry once per every light (though depth only) and once for the final image from camera.

0

Share this post


Link to post
Share on other sites

I am using function for projection and depth comparison:

//Position - world position of objects from G-bufferfloat shadowCast(float3 Position){	float4 texcoord = mul(float4(Position, 1.0), LightInvertViewProjection);	texcoord.x = ((texcoord.x / texcoord.w) * 0.5 ) + 0.5;	texcoord.y = ((texcoord.y / texcoord.w) * -0.5 ) + 0.5;	depth = tex2D(shadows, texcoord.xy);	return (texcoord.z < length(depth)*bias+offset);}
It works well for me, don't forget to tweak bias and offset to reduce acne and peter paning smile.png
.

Wait why is it the inverse of the view projection ?
What would the result of world space position multiplied by an inverse view projection be...again world space but this time in the light's space ?

UPDATE:
oh my god it works ;)

 

The problem I had all the time was that the view space reconstruction I had used did not work for the shadow projection.

Not sure why it works with my lighting though...

 

For anyone interested this is the code that works (ofc without any optimization):

VSO VS(VSI input)
{
    VSO output = (VSO)0;

    output.Position = input.Position;
	output.UV = input.UV;

	float3 positionVS = mul(input.Position, InverseProjection);
	output.ViewRay = float3(positionVS.xy / positionVS.z, 1.0f);


    return output;
}




float4 PS(VSO input) : SV_TARGET0
{
	float4 output = float4(0.0f, 0.0f, 0.0f, 1.0f);

	float3 ViewRay = input.ViewRay.xyz;
	float depth = DepthTarget.Sample(PointSampler, input.UV).r;

	float nearClip = 0.01f;
	float farClip = 100.0f;

	float ProjectionA = farClip / (farClip - nearClip);
	float ProjectionB = (-farClip * nearClip) / (farClip - nearClip);
	
	float linearDepth = ProjectionB / (depth - ProjectionA);
	float3 PositionVS = ViewRay * linearDepth;

	float4 PositionWS = mul(float4(PositionVS, 1.0f), InverseView);

	float4 texcoord = mul(PositionWS, LightInverseViewProjection);
	texcoord.x = ((texcoord.x / texcoord.w) * 0.5f ) + 0.5f;
	texcoord.y = ((texcoord.y / texcoord.w) * -0.5f ) + 0.5f;
	float shadowdepth = ShadowMap.Sample(PointSampler, texcoord.xy);

	float offset = 0.002f;

	float shadowFactor = (texcoord.z < length(shadowdepth) + offset);

	return shadowFactor;
}

 

 

Edited by lipsryme
0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0